Strapping tools or strappers come in a wide variety of types, from fully manual hand tools to automatic, table-top machines. Strapping tools can be designed and intended for use with different types of strap or strapping materials, such as metal strapping or plastic/polymeric strapping. Strappers for metal strapping materials can be automatic table-top or hand-held devices that are configured to seal the strap onto itself. The sealing function can be performed using a sealless configuration by forming interlocking keys in overlapping courses of the strap, or by applying a seal that is positioned over and crimped onto the overlapping strap courses.
There are two types of known hand-held devices for steel strap: manual tools that require an operator to exert one or more forces to tension the strap and form the seal; and pneumatically operated tools that perform the tension and sealing functions by actuation of one or more pneumatic motors. The manual tools can be fatiguing to operate for long periods of time and may be difficult to maneuver and manipulate in certain instances, for example when the seal is formed on the side of a package or load. Moreover, manual sealing typically requires multiple tools to tension the strap, form the seal and cut the sealed strap from its source.
Pneumatic tools, such as that disclosed in Crittenden, U.S. Pat. No. 6,079,457, commonly assigned with the present application and incorporated herein in its entirety by reference, function well; however, they require a source of compressed gas, such as air, and thus necessitate the use of hoses, compressed gas fittings and the like for operation. As such, the use of pneumatic tools may be limited in certain applications where, for example, the strapping operations are carried out at different locations throughout a manufacturing facility. Moreover, pneumatic tools employ pneumatic motors which can be costly, and pneumatic circuits which can be complex and require casting and machining operations in the manufacture of pneumatic circuit modules.
Accordingly, there is a need for a powered strapping tool that functions to tension strap around a load, form a seal in the overlapping courses of strap material and cut the sealed strap from its source. Desirably, such a tool is self-contained, is electrically and/or battery powered, and is thus portable and can be used throughout a facility at any location. More desirably still, such a tool can be used in a variety of operating modes.